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From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Doug Crawford <doug.crawford@intelight-its.com>,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: Freeze on ppc32 MPC8248 board with 5.2 kernel
Date: Tue, 13 Aug 2019 06:41:27 +0200	[thread overview]
Message-ID: <b0fdb52f-7a30-dcc7-5ec3-e01dd9bd1d44@c-s.fr> (raw)
In-Reply-To: <CAESxVDiyXu+=6+YmLej3K=i55h3=Z9JLA8JgrDn3fEQGUuSq7Q@mail.gmail.com>

Hi Doug,

Le 26/07/2019 à 00:30, Doug Crawford a écrit :
> We have a ppc32 MPC8248 board that is working perfectly with the 4.19 
> kernel.
> We have noticed two issues with the 5.2 kernel:

  Have you tried 5.0 and 5.1 ?

> 
> 1) If the new CONFIG_PPC_KUAP (kernel userspace access protection) is 
> enabled the kernel freezes right after initializing all the drivers and 
> just before starting /sbin/init.

Can you provide your .config ?

Can you also provide the output of the boot console ?

> 
> 2) If CONFIG_PPC_KUAP is disabled the system starts up, but any user 
> space program will hang indefinitely after calling the GCC atomic 
> "__sync_bool_compare_and_swap".  This happens when nginx starts.  The 
> same nginx binary works fine on a 4.19 kernel.

Can you provide 'dmesg' ?

What version of GCC do you use ?

Have you tried a simple program doing nothing else than 
__sync_bool_compare_and_swap() ?

Can you provide a disassembly of the function that uses 
__sync_bool_compare_and_swap() ?

Thanks
Christophe

      reply	other threads:[~2019-08-13  4:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-25 22:30 Freeze on ppc32 MPC8248 board with 5.2 kernel Doug Crawford
2019-08-13  4:41 ` Christophe Leroy [this message]

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